Method for verifying latch engagement for cargo handling systems

ABSTRACT

A cargo handling system is disclosed. In various embodiments, the cargo handling system includes a power drive unit having a drive roller configured to impart movement to a unit load device; a first restraint; and a first sensor configured to detect movement of the unit load device with respect to a parked location following deployment of the first restraint and activation of the drive roller.

FIELD

The present disclosure relates generally to cargo handling systems and,more particularly, to power drive units and control systems used totransport cargo in cargo handling systems.

BACKGROUND

Cargo handling systems for aircraft typically include various tracks androllers disposed on a cargo deck that spans the length of a cargocompartment. Cargo may be loaded from an entrance of the aircraft andtransported by the cargo system to forward or aft locations, dependingupon the configuration of the aircraft. Cargo handling systems, such as,for example, those used on aircraft for transport of heavy containerizedcargo or pallets, also referred to herein as unit load devices (ULDs),typically include roller trays containing transport rollers that supportand transport the containerized cargo or pallets. Motor driven rollersare typically employed in these systems. In certain aircraft, aplurality of motor driven power drive units (PDUs) is used to propel thecontainers or pallets within the cargo compartment. This configurationfacilitates transportation of the containers or pallets within the cargocompartment by one or more operators or agent-based systems controllingoperation of the PDUs.

SUMMARY

A cargo handling system is disclosed. In various embodiments, the cargohandling system includes a power drive unit having a drive rollerconfigured to impart movement to a unit load device; a first restraint;and a first sensor configured to detect movement of the unit load devicewith respect to a parked location following deployment of the firstrestraint and activation of the drive roller.

In various embodiments, a second sensor is configured to detectdeployment of the first restraint. In various embodiments, the firstsensor is positioned proximate a conveyance surface of the cargohandling system. In various embodiments, the second sensor is positionedproximate the conveyance surface. In various embodiments, the firstsensor is a unit load device sensor. In various embodiments, the secondsensor is at least one of an encoder and a limit switch. In variousembodiments, the first sensor is positioned proximate a surface externalto the cargo handling system. In various embodiments, the first sensoris an external vision sensor system.

In various embodiments, the first restraint is a first latch configuredto engage the unit load device. In various embodiments, the first latchis configured to engage a first slot portion positioned on the unit loaddevice. In various embodiments, the second sensor is configured todetect deployment of the first latch.

In various embodiments, the system includes a second restraint and asecond sensor configured to detect deployment of the first restraint andthe second restraint. In various embodiments, the first restraint is afirst latch configured to engage the unit load device and the secondrestrain is a second latch configured to engage the unit load device.

A method for storing and restraining cargo is disclosed. In variousembodiments, the method includes the steps of positioning a unit loaddevice at a parked location on a conveyance surface and in contact witha drive roller; deploying a restraint to engage the unit load device;and verifying engagement of the restraint with the unit load device byactivating the drive roller and detecting movement of the unit loaddevice with respect to the conveyance surface.

In various embodiments, the method requires verifying deployment of therestraint prior to verifying engagement of the restraint with the unitload device. In various embodiments, the restraint includes a firstrestraint device and a second restraint device. In various embodiments,verifying engagement of the restraint with the unit load devicecomprises use of a first sensor configured for the detecting movement ofthe unit load device with respect to the conveyance surface. In variousembodiments, verifying deployment of the restraint comprises use of asecond sensor configured to detect movement of at least one of the firstrestraint device and the second restraint device.

A system for storing and restraining cargo on a cargo deck is disclosed.In various embodiments, the system includes a power drive unit having adrive roller configured to impart movement to a unit load device withrespect to a conveyance surface; a first restraint configured to engagethe unit load device; a second restraint configured to engage the unitload device; a first sensor configured to detect movement of the unitload device with respect to a parked location following deployment ofthe first restraint and the second restraint and activation of the driveroller; and a second sensor configured to detect deployment of the firstrestraint and the second restraint. In various embodiments, the firstrestraint is a first latch configured to engage the unit load device andthe second restrain is a second latch configured to engage the unit loaddevice.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the following detailed description andclaims in connection with the following drawings. While the drawingsillustrate various embodiments employing the principles describedherein, the drawings do not limit the scope of the claims.

FIG. 1A illustrates a schematic view of an aircraft being loaded withcargo, in accordance with various embodiments;

FIG. 1B illustrates a portion of a cargo handling system, in accordancewith various embodiments;

FIG. 2 illustrates a portion of a cargo handling system, in accordancewith various embodiments;

FIGS. 3A and 3B illustrate a schematic view of a cargo deck having acargo handling system with a plurality of PDUs, in accordance withvarious embodiments;

FIG. 4 illustrates a schematic view of a portion of a cargo handlingsystem, in accordance with various embodiments; and

FIG. 5 illustrates a method of verifying latch engagement, in accordancewith various embodiments.

DETAILED DESCRIPTION

The following detailed description of various embodiments herein makesreference to the accompanying drawings, which show various embodimentsby way of illustration. While these various embodiments are described insufficient detail to enable those skilled in the art to practice thedisclosure, it should be understood that other embodiments may berealized and that changes may be made without departing from the scopeof the disclosure. Thus, the detailed description herein is presentedfor purposes of illustration only and not of limitation. Furthermore,any reference to singular includes plural embodiments, and any referenceto more than one component or step may include a singular embodiment orstep. Also, any reference to attached, fixed, connected, or the like mayinclude permanent, removable, temporary, partial, full or any otherpossible attachment option. Additionally, any reference to withoutcontact (or similar phrases) may also include reduced contact or minimalcontact. It should also be understood that unless specifically statedotherwise, references to “a,” “an” or “the” may include one or more thanone and that reference to an item in the singular may also include theitem in the plural. Further, all ranges may include upper and lowervalues and all ranges and ratio limits disclosed herein may be combined.

With reference to FIG. 1A, a schematic view of an aircraft 10 having acargo deck 12 located within a cargo compartment 14 is illustrated, inaccordance with various embodiments. The aircraft 10 may comprise acargo load door 16 located, for example, at one side of a fuselagestructure of the aircraft 10. A unit load device (ULD) 20, in the formof a container or pallet, for example, may be loaded through the cargoload door 16 and onto the cargo deck 12 of the aircraft 10 or,conversely, unloaded from the cargo deck 12 of the aircraft 10. Ingeneral, ULDs are available in various sizes and capacities, and aretypically standardized in dimension and shape. Once loaded with itemsdestined for shipment, the ULD 20 is transferred to the aircraft 10 andthen loaded onto the aircraft 10 through the cargo load door 16 using aconveyor ramp, scissor lift or the like. Once inside the aircraft 10,the ULD 20 is moved within the cargo compartment 14 to a final stowedposition. Multiple ULDs may be brought on-board the aircraft 10, witheach ULD 20 being placed in a respective stowed position on the cargodeck 12. After the aircraft 10 has reached its destination, each ULD 20is unloaded from the aircraft 10 in similar fashion, but in reversesequence to the loading procedure. To facilitate movement of the ULD 20along the cargo deck 12, the aircraft 10 may include a cargo handlingsystem as described herein in accordance with various embodiments.

Referring now to FIG. 1B, a portion of a cargo handling system 100 isillustrated, in accordance with various embodiments. The cargo handlingsystem 100 is illustrated with reference to an XYZ coordinate system,with the X-direction extending longitudinally and the Z-directionextending vertically with respect to an aircraft in which the cargohandling system 100 is positioned, such as, for example, the aircraft 10described above with reference to FIG. 1A. In various embodiments, thecargo handling system 100 may define a conveyance surface 102 having aplurality of trays 104 supported by a cargo deck 112, such as, forexample, the cargo deck 12 described above with reference to FIG. 1A.The plurality of trays 104 may be configured to support a unit loaddevice (ULD) 120 (or a plurality of ULDs), such as, for example, theunit load device (ULD) 20 described above with reference to FIG. 1A. Invarious embodiments, the ULD 120 may comprise a container or a palletconfigured to hold cargo as described above. In various embodiments, theplurality of trays 104 is disposed throughout the cargo deck 112 and maysupport a plurality of conveyance rollers 106, where one or more or allof the plurality of conveyance rollers 106 is a passive roller.

In various embodiments, the plurality of trays 104 may further support aplurality of power drive units (PDUs) 110, each of which may include oneor more drive rollers 108 that may be actively powered by a motor. Invarious embodiments, one or more of the plurality of trays 104 ispositioned longitudinally along the cargo deck 112—e.g., along theX-direction extending from the forward end to the aft end of theaircraft. In various embodiments, the plurality of conveyance rollers106 and the one or more drive rollers 108 may be configured tofacilitate transport of the ULD 120 in the forward and the aftdirections along the conveyance surface 102. During loading andunloading, the ULD 120 may variously contact the one or more driverollers 108 to provide a motive force for transporting the ULD 120 alongthe conveyance surface 102. Each of the plurality of PDUs 110 mayinclude an actuator, such as, for example, an electrically operatedmotor, configured to drive the one or more drive rollers 108corresponding with each such PDU. In various embodiments, the one ormore drive rollers 108 may be raised from a lowered position beneath theconveyance surface 102 to an elevated position above the conveyancesurface 102 by the corresponding PDU. As used with respect to cargohandling system 100, the term “beneath” may refer to the negativeZ-direction, and the term “above” may refer to the positive Z-directionwith respect to the conveyance surface 102. In the elevated position,the one or more drive rollers 108 variously contact and drive the ULD120 that otherwise rides on the plurality of conveyance rollers 106.Other types of PDUs, which can also be used in various embodiments ofthe present disclosure, may include a drive roller 108 that is held orbiased in a position above the conveyance surface by a spring. PDUs asdisclosed herein may be any type of electrically powered rollers thatmay be selectively energized to propel or drive the ULD 120 in a desireddirection over the cargo deck 112 of the aircraft. The plurality oftrays 104 may further support a plurality of restraint devices 114. Invarious embodiments, each of the plurality of restraint devices 114 maybe configured to rotate downward as the ULD 120 passes over and alongthe conveyance surface 102. Once the ULD 120 passes over any such one ofthe plurality of restraint devices 114, such restraint device may returnto its upright position, either by a motor driven actuator or a biasmember, thereby restraining or preventing the ULD 120 from translatingin the opposite direction.

In various embodiments, the cargo handling system 100 may include asystem controller 130 in communication with each of the plurality ofPDUs 110 via a plurality of channels 132. Each of the plurality ofchannels 132 may be a data bus, such as, for example, a controller areanetwork (CAN) bus. An operator may selectively control operation of theplurality of PDUs 110 using the system controller 130. In variousembodiments, the system controller 130 may be configured to selectivelyactivate or deactivate the plurality of PDUs 110. Thus, the cargohandling system 100 may receive operator input through the systemcontroller 130 to control the plurality of PDUs 110 in order tomanipulate movement of the ULD 120 over the conveyance surface 102 andinto a desired position on the cargo deck 112. In various embodiments,the system controller 130 may include a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or some otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof. The cargo handlingsystem 100 may also include a power source 126 configured to supplypower to the plurality of PDUs 110 or to the plurality of restraintdevices 114 via one or more power busses 128. As described below, invarious embodiments, the system controller 130 may be complimented by orsubstituted with an agent-based control system, whereby control of eachPDU and associated componentry—e.g., the restraint devices—is performedby individual unit controllers associated with each of the PDUs andconfigured to communicate between each other.

Referring now to FIG. 2, a PDU 210, such as for example, one of theplurality of PDUs 110 described above with reference to FIG. 1B, isillustrated disposed in a tray 204, in accordance with variousembodiments. The PDU 210 may rotate the drive roller 208 in one of twopossible directions (e.g., clockwise or counterclockwise) to propel theULD in a direction parallel to the longitudinal axis B-B′ of the tray204. The PDU 210 may comprise a unit controller 240, a unit motor 242and a drive roller 208 mounted within an interior section 205 of thetray 204. The drive roller 208 may comprise a cylindrical wheel coupledto a drive shaft and configured to rotate about an axis A-A′. The driveroller 208 may be in mechanical communication with the unit motor 242,which may be, for example, an electromagnetic, electromechanical orelectrohydraulic actuator or other servomechanism. The PDU 210 mayfurther include gear assemblies and other related components for turningor raising the drive roller 208 so that the drive roller 208 may extend,at least partially, above a conveyance surface 202 which, in variousembodiments, may be defined as the uppermost surface 203 of the tray204. At least partial extension of the drive roller 208 above theconveyance surface 202 facilitates contact between the drive roller 208and a lower surface of a ULD, such as, for example, the ULD 120described above with reference to FIG. 1B. In various embodiments, theunit controller 240 is configured to control operation of the driveroller 208. The unit controller 240 may include a processor and atangible, non-transitory memory. The processor may comprise one or morelogic modules that implement logic to control rotation and elevation ofthe drive roller 208. In various embodiments, the PDU 210 may compriseother electrical devices to implement drive logic. In variousembodiments, a connector 244 is used to couple the electronics of thePDU 210 to a power source and a system controller, such as, for example,the system controller 130 described above with reference to FIG. 1B. Theconnector 244 may have pins or slots and may be configured to couple toa wiring harness having pin programming. The unit controller 240 may beconfigured to receive commands from the system controller through theconnector 244 in order to control operation of the unit motor 242.

In addition, a restraint device 214, such as, for example, one of theplurality of restraint devices 114 described above with reference toFIG. 1B, is illustrated as disposed within the tray 204 and configuredto operate between a stowed position, whereby the ULD may pass over therestraint device, and a deployed position (as illustrated), whereby theULD is restrained or prevented from translation in a longitudinaldirection (e.g., along a longitudinal axis B-B′) without the restraintdevice 214 first being returned to the stowed position. The restraintdevice 214 includes a restraint controller 215 and a restraint motor217. In various embodiments, the restraint device 214 may be inmechanical communication with the restraint motor 217, which may be, forexample, an electromagnetic, electromechanical or electrohydraulicactuator or other servomechanism. In various embodiments, the restraintcontroller 215 is configured to control operation of the restraintdevice 214. The restraint controller 215 may include a processor and atangible, non-transitory memory. The processor may comprise one or morelogic modules that implement logic to control operation of the restraintdevice 214 between the stowed and the deployed positions.

In various embodiments, the PDU 210 may also include a radio frequencyidentification device or RFID device 246, or similar device, configuredto store, transmit or receive information or data—e.g., operationalstatus or location data. Additionally, a ULD sensor 219 may be disposedwithin the tray 204 and configured to detect the presence of a ULD asthe ULD is positioned over or proximate to the PDU 210 or the restraintdevice 214. In various embodiments, the ULD sensor 219 may include anytype of sensor capable of detecting the presence of a ULD. For example,in various embodiments, the ULD sensor 219 may comprise a proximitysensor, a capacitive sensor, a capacitive displacement sensor, a Dopplereffect sensor, an eddy-current sensor, a laser rangefinder sensor, amagnetic sensor, an active or passive optical sensor, an active orpassive thermal sensor, a photocell sensor, a radar sensor, a sonarsensor, a lidar sensor, an ultrasonic sensor or the like.

Referring now to FIG. 3A, a schematic view of a cargo handling system300 positioned on a cargo deck 312 of an aircraft is illustrated, inaccordance with various embodiments. The cargo deck 312 may comprise aplurality of PDUs 310, generally arranged in a matrix configurationabout the cargo deck 312. Associated with each of the plurality of PDUs310 may be one or more drive rollers 308 and a restraint device 314. Invarious embodiments, the plurality of PDUs 310, the one or more driverollers 308 and the restraint device 314 share similar characteristicsand modes of operation as the PDU 210, drive roller 208 and restraintdevice 214 described above with reference to FIG. 2. Each of the one ormore drive rollers 308 is generally configured to selectively protrudefrom a conveyance surface 302 of the cargo deck 312 in order to engagewith a surface of a ULD 320 as it is guided onto and over the conveyancesurface 302 during loading and unloading operations. A plurality ofconveyance rollers 306 may be arranged among the plurality of PDUs 310in a matrix configuration as well. The plurality of conveyance rollers306 may comprise passive elements, and may include roller ball units 351that serve as stabilizing and guiding apparatus for the ULD 320 as it isconveyed over the conveyance surface 302 by the plurality of PDUs 310.

In various embodiments, the cargo handling system 300 or, moreparticularly, the conveyance surface 302, is divided into a plurality ofsections. As illustrated, for example, the conveyance surface 302 mayinclude a port-side track and a starboard-side track along which aplurality of ULDs may be stowed in parallel columns during flight.Further, the conveyance surface 302 may be divided into an aft sectionand a forward section. Thus, the port-side and starboard-side tracks, invarious embodiments and as illustrated, may be divided into foursections—e.g., a forward port-side section 350, a forward starboard-sidesection 352, an aft port-side section 354 and an aft starboard-sidesection 356. The conveyance surface 302 may also have a lateral section358, which may be used to transport the ULD 320 onto and off of theconveyance surface 302 as well as transfer the ULD 320 between theport-side and starboard-side tracks and between the aft section and theforward section. The configurations described above and illustrated inFIG. 3 are exemplary only and may be varied depending on the context,including the numbers of the various components used to convey the ULD320 over the conveyance surface 302. In various embodiments, forexample, configurations having three or more track configurations,rather than the two-track configuration illustrated in FIG. 3, may beemployed.

Each of the aforementioned sections—i.e., the forward port-side section350, the forward starboard-side section 352, the aft port-side section354 and the aft starboard-side section 356—may include one or more ofthe plurality of PDUs 310. Each one of the plurality of PDUs 310 has aphysical location on the conveyance surface 302 that corresponds to alogical address within the cargo handling system 300. For purposes ofillustration, the forward port-side section 350 is shown having a firstPDU 310-1, a second PDU 310-2, a third PDU 310-3, a fourth PDU 310-4, afifth PDU 310-5 and an N-th PDU 310-N. The aforementioned individualPDUs are located, respectively, at a first location 313-1, a secondlocation 313-2, a third location 313-3, a fourth location 313-4, a fifthlocation 313-5 and an N-th location 303-N. In various embodiments, thelocation of each of the aforementioned individual PDUs on the conveyancesurface 302 may have a unique location (or address) identifier, which,in various embodiments, may be stored in an RFID device, such as, forexample, the RFID device 246 described above with reference to FIG. 2.

In various embodiments, an operator may control operation of theplurality of PDUs 310 using one or more control interfaces of a systemcontroller 330, such as, for example, the system controller 130described above with reference to FIG. 1B. For example, an operator mayselectively control the operation of the plurality of PDUs 310 throughan interface, such as, for example, a master control panel (MCP) 331. Invarious embodiments, the cargo handling system 300 may also include oneor more local control panels (LCP) 334. In various embodiments, themaster control panel 331 may communicate with the local control panels334. The master control panel 331 or the local control panels 334 mayalso be configured to communicate with or send or receive controlsignals or command signals to or from each of the plurality of PDUs 310or to a subset of the plurality of PDUs 310, such as, for example, theaforementioned individual PDUs described above with reference to theforward port-side section 350. For example, a first local control panelLCP-1 may be configured to communicate with the PDUs residing in theforward port-side section 350, a second local control panel LCP-2 may beconfigured to communicate with the PDUs residing in the forwardstarboard-side section 352, and one or more additional local controlpanels LCP-i may be in communication with the PDUs of one or more of theaft port-side section 354, the aft starboard-side section 356 and thelateral section 358. Thus, the master control panel 331 or local controlpanels 334 may be configured to allow an operator to selectively engageor activate one or more of the plurality of PDUs 310 to propel the ULD320 along conveyance surface 302.

In various embodiments, each of the plurality of PDUs 310 may beconfigured to receive a command from the master control panel 331 or oneor more of the local control panels 334. In various embodiments, thecommands may be sent or information exchanged over a channel 332, whichmay provide a communication link between the system controller 330 andeach of the plurality of PDUs 310. In various embodiments, a commandsignal sent from the system controller 330 may include one or morelogical addresses, each of which may correspond to a physical address ofone of the plurality of PDUs 310. Each of the plurality of PDUs 310 thatreceives the command signal may determine if the command signal isintended for that particular PDU by comparing its own address to theaddress included in the command signal.

With reference to FIG. 3B, a schematic view of a portion of the cargohandling system 300 and the cargo deck 312 is shown in accordance withvarious embodiments. By way of non-limiting example, the systemcontroller 330 is configured to send a command signal through thechannel 332 to at least the first PDU 310-1 and the second PDU 310-2 ofthe forward port-side section 350. The command signal may, for example,comprise an instruction to activate or deactivate a first motor 342-1associated with the first PDU 310-1 or a second motor 342-2 associatedwith the second PDU 310-2. The command signal may also comprise a firstaddress that corresponds to the first location 313-1 or a second addressthat corresponds to the second location 313-2. A first unit controller340-1 of the first PDU 310-1 may receive the command signal through afirst connector 344-1 and a second unit controller 340-2 of the secondPDU 310-2 may receive the command signal through a second connector344-2. Following receipt of the signal, the first unit controller 340-1and the second unit controller 340-2 may determine whether the commandis intended to affect operation of the first PDU 310-1 or the second PDU310-2, respectively, by comparing a location address contained withinthe signal to a known address associated with the respective PDUs. Invarious embodiments, the first address associated with the first PDU310-1 may be stored in a first RFID device 346-1 and the second addressassociated with the second PDU 310-2 may be stored in a second RFIDdevice 346-2. Additionally, a ULD sensor, such as, for example, the ULDsensor 219 described above with reference to FIG. 2 may be disposedproximate each PDU and configured to detect the presence of a ULD as theULD is positioned over or proximate to the PDU. Accordingly, a first ULDsensor 319-1 may be disposed proximate or within the first PDU 310-1 anda second ULD sensor 319-2 may be disposed proximate or within the secondPDU 310-2.

Turning now to FIG. 4, a schematic diagram of a portion of a cargohandling system 400 is illustrated, such as, for example, the cargohandling system 100 described above with reference to FIG. 1B. Similarto the cargo handling systems previously described, the cargo handlingsystem 400 includes a PDU 410 configured to operate a drive roller 408and one or more conveyance rollers 406. The drive roller and the one ormore conveyance rollers 406 are configured to transport a ULD 420 over aconveyance surface 402, which is formed by one or more trays 404disposed on a cargo deck 412. During a loading sequence, the ULD 420 ispropelled by the drive roller 408 into a stored or parked position, asillustrated in FIG. 4. Prior to or after reaching the stowed or parkedposition, a forward latch 414-1 (or first latch or first restraintdevice) is rotated from a stowed position (dashed lines) to its deployedposition, as illustrated. In various embodiments, the forward latch414-1 includes a hook portion 415 that is configured to engage a slotportion 417 in the ULD 420 that corresponds to the hook portion 415. Invarious embodiments, the slot portion 417 may comprise a lip thatextends outwardly from a surface of the ULD 420. Following the ULD 420reaching the stowed or parked position, an aft latch 414-2 (or secondlatch or second restraint device) is rotated from a stowed position, asillustrated, to a deployed position (dashed lines).

Once the forward latch 414-1 and the aft latch 414-2 are rotated totheir respective deployed positions, various steps, as described below,may be taken to verify proper engagement of the latches with the ULD420. For example, initial deployment of the laches, from their stowed todeployed positions, may be verified through sensors, such as, forexample, a limit switch 407 or an encoder 409. In various embodiments,subsequent verification of proper engagement of the forward latch 414-1and the aft latch 414-2 with the ULD 420 may be carried by driving theULD 420 in the forward and aft directions by the drive roller 408 anddetecting through various methods any movement or motion of the ULD 420.By way of non-limiting examples, motion detection of the ULD 420 may becarried out using an external vision sensor system 411 secured ormounted to an external surface such as a floor or wall of an aircraft.In various embodiments, the external vision system may comprise, forexample, a lidar system (light detection and ranging system). In variousembodiments, motion detection of the ULD 420 may also be carried outusing a torque monitoring system 413 associated with the PDU 410 or asensor system 419 associated with the PDU 410, such as, for example, theULD sensor 219 described above with reference to FIG. 2.

Referring now to FIG. 5, a method 500 describing various steps taken toverify engagement of a ULD within a cargo handling system, such as, forexample, the cargo handling system 400 and ULD 420 described above withreference to FIG. 4 is provided. At a first step 501, a forward latch ismoved (e.g., rotated) to a deployed position. In a second step 502, aULD is driven to a parked position by one or more PDUs. At the parkedposition, at least one drive roller remains in contact with a lowersurface of the ULD. In a third step 503, an aft latch is deployed. Invarious embodiments, during a fourth step 504, the deployment of boththe forward latch and the aft latch is verified. In various embodiments,the engagement of the forward latch and the aft latch with the ULD maybe carried out using limit switches or encoders.

In a fifth step 505, engagement of the forward latch and the aft latchwith the ULD is verified. In various embodiments, engagement of thelatches with the ULD may be carried out using an external vision sensorsystem, employing, for example, point cloud or edge analysis imageprocessing. In various embodiments, engagement of the latches with theULD may be carried out using a torque monitoring system that monitors,for example, traction control or peak loads on impact. For example, ifthe ULD is not properly engaged, the torque experienced by a power driveunit motor may fall below a threshold value, indicating movement of theULD. Similarly, a measured impact load upon driving the motor maylikewise fall below a threshold value if the ULD is not properlyengaged, also indicating movement of the ULD. An external sensor systemmay also be employed to detect movement of the ULD when the drive rolleris rotated.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the disclosure. The scope of the disclosure is accordinglyto be limited by nothing other than the appended claims, in whichreference to an element in the singular is not intended to mean “one andonly one” unless explicitly so stated, but rather “one or more.”Moreover, where a phrase similar to “at least one of A, B, or C” is usedin the claims, it is intended that the phrase be interpreted to meanthat A alone may be present in an embodiment, B alone may be present inan embodiment, C alone may be present in an embodiment, or that anycombination of the elements A, B and C may be present in a singleembodiment; for example, A and B, A and C, B and C, or A and B and C.Different cross-hatching is used throughout the figures to denotedifferent parts but not necessarily to denote the same or differentmaterials.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “one embodiment,” “an embodiment,”“various embodiments,” etc., indicate that the embodiment described mayinclude a particular feature, structure, or characteristic, but everyembodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed. After reading the description, it will be apparent to oneskilled in the relevant art(s) how to implement the disclosure inalternative embodiments.

In various embodiments, system program instructions or controllerinstructions may be loaded onto a tangible, non-transitory,computer-readable medium (also referred to herein as a tangible,non-transitory, memory) having instructions stored thereon that, inresponse to execution by a controller, cause the controller to performvarious operations. The term “non-transitory” is to be understood toremove only propagating transitory signals per se from the claim scopeand does not relinquish rights to all standard computer-readable mediathat are not only propagating transitory signals per se. Stated anotherway, the meaning of the term “non-transitory computer-readable medium”and “non-transitory computer-readable storage medium” should beconstrued to exclude only those types of transitory computer-readablemedia that were found by In Re Nuijten to fall outside the scope ofpatentable subject matter under 35 U.S.C. § 101.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. 112(f) unless the element is expressly recitedusing the phrase “means for.” As used herein, the terms “comprises,”“comprising,” or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

Finally, it should be understood that any of the above describedconcepts can be used alone or in combination with any or all of theother above described concepts. Although various embodiments have beendisclosed and described, one of ordinary skill in this art wouldrecognize that certain modifications would come within the scope of thisdisclosure. Accordingly, the description is not intended to beexhaustive or to limit the principles described or illustrated herein toany precise form. Many modifications and variations are possible inlight of the above teaching.

What is claimed is:
 1. A cargo handling system, comprising: a powerdrive unit having a drive roller configured to impart movement to a unitload device; a first restraint; and a first sensor configured to detectmovement of the unit load device with respect to a parked locationfollowing deployment of the first restraint and activation of the driveroller.
 2. The cargo handling system of claim 1, further comprising asecond sensor configured to detect deployment of the first restraint. 3.The cargo handling system of claim 2, wherein the first sensor ispositioned proximate a conveyance surface of the cargo handling system.4. The cargo handling system of claim 3, wherein the second sensor ispositioned proximate the conveyance surface.
 5. The cargo handlingsystem of claim 4, wherein the first sensor is a unit load devicesensor.
 6. The cargo handling system of claim 5, wherein the secondsensor is at least one of an encoder and a limit switch.
 7. The cargohandling system of claim 2, wherein the first sensor is positionedproximate a surface external to the cargo handling system.
 8. The cargohandling system of claim 7, wherein the first sensor is an externalvision sensor system.
 9. The cargo handling system of claim 2, whereinthe first restraint is a first latch configured to engage the unit loaddevice.
 10. The cargo handling system of claim 9, wherein the firstlatch is configured to engage a first slot portion positioned on theunit load device.
 11. The cargo handling system of claim 10, wherein thesecond sensor is configured to detect deployment of the first latch. 12.The cargo handling system of claim 1, further comprising a secondrestraint and a second sensor configured to detect deployment of thefirst restraint and the second restraint.
 13. The cargo handling systemof claim 12, wherein the first restraint is a first latch configured toengage the unit load device and the second restraint is a second latchconfigured to engage the unit load device.
 14. A method for storing andrestraining cargo, comprising: positioning a unit load device at aparked location on a conveyance surface and in contact with a driveroller; deploying a restraint to engage the unit load device; andverifying engagement of the restraint with the unit load device byactivating the drive roller and detecting movement of the unit loaddevice with respect to the conveyance surface.
 15. The method of claim14, further comprising verifying deployment of the restraint prior tothe verifying engagement of the restraint with the unit load device. 16.The method of claim 15, wherein the restraint includes a first restraintdevice and a second restraint device.
 17. The method of claim 16,wherein the verifying engagement of the restraint with the unit loaddevice comprises use of a first sensor configured for the detectingmovement of the unit load device with respect to the conveyance surface.18. The method of claim 17, wherein the verifying deployment of therestraint comprises use of a second sensor configured to detect movementof at least one of the first restraint device and the second restraintdevice.
 19. A system for storing and restraining cargo on a cargo deck,comprising: a power drive unit having a drive roller configured toimpart movement to a unit load device with respect to a conveyancesurface; a first restraint configured to engage the unit load device; asecond restraint configured to engage the unit load device; a firstsensor configured to detect movement of the unit load device withrespect to a parked location following deployment of the first restraintand the second restraint and activation of the drive roller; and asecond sensor configured to detect deployment of the first restraint andthe second restraint.
 20. The system of claim 19, wherein the firstrestraint is a first latch configured to engage the unit load device andthe second restraint is a second latch configured to engage the unitload device.